Refrigeration system having means for heating the bottom sections of tubular ice generators



p 1, 1965 N. E. F. NILSSON ETAL 3,205,945

REFRIGERATION SYSTEM HAVING MEANS FOR HEATING THE BOTTOM SECTIONS OF TUBULAR ICE GENERATORS Filed Nov. 21. 1961 United States Patent 3,206,945 REFRIGERATION SYSTEM HAVING MEANS FOR HEATING THE BOTTOM SECTIONS OF TUBU- LAR ICE GENERATORS Nils Edvin Folke Nilsson, Klingsbergsgatan 21, and Lembit Muda, Norrgardsvagen 71, both of Norrkoping, Sweden Filed Nov. 21, 1961, Ser. No. 153,873 Claims priority, application Sweden, Nov. 26, 1960, 11,443/ 60 2 Claims. (Cl. 62352) The present invention relates to a refrigeration system in which the bottom section of a .tube ice generator forming part of the refrigerating system is heated, and in which system the ice is freed from the tubes of the generator by heating them by means of condensing high pressure vapor. This heating, which must be effected rapidly in order not to melt the ice rods in an undesired degree, does not, as a rule, extend sufiiciently to the bottom ends of the tubes because of the fact that the heat transmission near the bottom of the generator is very bad, since the condensate flowing downwards along the tubes isolates the bottom ends thereof. It is therefore required to apply additional heat to the bottom section of the ice generator in order to secure a satisfactory result.

It is an object of the invention to provide a system in which said additional heat is supplied to the bottom section of the ice generator without the need of any additional source of heat.

To this end the condensate obtained in the refrigerator system is used to evaporate a medium contained in a heat exchanger coupled .to the bottom portion of the ice generator and carry the resulting vapor from said heat exchanger into the bottom section of the tube ice generator and let it condense there and allow the condensate to return to the heat exchanger.

Since the heat required for this operation is taken from the normal condensate formed in the system there are no losses and the operational economy resulting will be excellent. By allowing the condensate in the heat exchanger to evaporate the medium which then condenses at the bottom of the ice generator, a uniform temperature may be obtained along the entire length of the tubes, which in its turn secures a faster and more reliable freeing of the ice rods formed inside the tubes.

In the accompanying drawing an embodiment of a refrigerating system, to which the invention is applied, is illustrated diagrammatically.

The refrigerating system shown comprises the following main elements: A compressor 1, a consenser 2 containing cooling coil 2a, a tube ice generator 3, and a hollow surge drum 4. These elements are connected by pipes, in which, while ice is being made, a refrigerant flows, as indicated by the arrows. Inserted in the pipe extending between the condenser 2 and the surge drum 4 is an expansion valve 5.

The ice generator 3 is of the conventional tubular type, containing a plurality of vertical tubes 7 through which water is passed downwards from an intake 3b at the top. By contact with the cool tube walls the water will be frozen so as to form ice tubes the walls of which gradually 3,206,945 Patented Sept. 21, 1965 "ice grow thicker inwardly. The refrigerant returns to surge drum 4 from ice generator 3 through a pipe 3a having a shut-off valve d located therein.

At the bottom of the generator there is a sealed space 6 surrounding the bottom end of the bundle of tubes 7. Communicating with said space by pipes 8 and 9 is a heat exchanger 10 containing for instance, a refrigerant.

A pipe loop 11 formed by the conduit connecting the condenser 2 to the surge drum 4, is located inside the heat exchanger 10. Condensate passing through loop 11 delivers part of its heat contents to the refrigerant contained in heat exchanger 10. As a result, the refrigerant therein evaporates and passes through pipe 8 to space 6 where it delivers heat to the tubes, condenses and flows back to the heat exchanger through pipe 9. In the harvesting operation hot vapor is passed from the compressor 1 through the conduit c to the space around the tubes 7 of the ice generator 3. During this time valve dis held closed. The hot vapor forces the liquid in generator 3 out of its place and delivers its heat to the tubes 7, causing the ice rods therein to come loose.

We claim:

1. In a refrigeration system including a set of upright ice generating tubes, a compressor, a condenser, and an evaporator, conduits connecting said compressor, condenser and evaporator, means enclosing a space at the bottom portions of said tubes; means for heating said space and the bottom ends of said tubes, said means including a heat exchanger for receiving an evaporable liquid, connections between said heat exchanger and said space surrounding the lower ends of said ice generating tubes, and heat emitting means located in said heat exchanger, said heat emitting means being connected to said conduit interconnecting said condenser and said evaporator of the refrigeration system.

2. A device as claimed in claim 1, in which said heat emitting means located in the heat exchanger comprises a loop of the conduit interconnecting the condenser and the evaporator of the refrigeration system.

References Cited by the Examiner UNITED STATES PATENTS 837,499 12/06 Perkins et a1 165-105 2,313,087 3/43 Parr et a1. 165-105 2,487,851 11/49 Charland l-105 X 2,700,280 1/ 55 Heuser 62344 2,721,452 10/55 Brandin et al 62352 2,749,721 6/56 Trepaud 62352 2,775,098 12/56 Mac Leod 6273 2,921,443 l/60 Lee 6273 2,967,402 1/ 61 Wilbushewich 62352 3,036,443 5/62 Trepaud 62252 FOREIGN PATENTS 204,609 11/08 Germany.

OTHER REFERENCES German application 1,096,935, printed Dec. 1, 1961.

ROBERT A. OLEARY, Primary Examiner.

MEYER PERLIN, Examiner, 

1. IN A REFRIGERATION SYSTEM INCLUDING A SET OF UPRIGHT ICE GENERATING TUBES, A COMPRESSOR, A CONDENSER, AND AN EVAPORATOR, CONDUITS CONNECTING SAID COMPRESSOR, CONDENSER AND EVAPORATOR, MEANS ENCLOSING A SPACE AT THE BOTTOM PORTIONS OF SAID TUBES; MEANS FOR HEATING SAID SPACE AND THE BOTTOM ENDS OF SAID TUBES, SAID MEANS INCLUDING A HEAT EXCHANGER FOR RECEIVING AN EVAPORABLE LIQUID, CONNECTIONS BETWEEN SAAID HEAT EXCHANGER AND SAID SPACE SURROUNDING THE LOWER ENDS OF SAID ICE GENERATING TUBES, AND HEAT EMITTING MEANS LOCATED IN SAID HEAT EXCHANGER, SAID HEAT EMITTING MEANS BEING CONNECTED TO SAID CONDUIT INTERCONNECTING SAID CONDESNER AND SAID EVAPORATOR OF THE REFRIGERATION SYSTEM. 